The chain grate is currently the most widely used type of mechanized layer-fired equipment in industrial boilers and is extensively employed in industrial boilers (such as those burning loose coal and biomass). Its structure resembles a moving track, feeding fuel into the furnace through a hopper chute. As the grate moves slowly, the fuel sequentially undergoes preheating, drying, ignition, and combustion until complete combustion is achieved, followed by automatic ash discharge. It features continuous fuel feeding and automatic ash removal. It is widely used in industries such as textiles, apparel, food and beverage, chemicals, cement curing, and disinfection.

I. What Is a Chain Grate?

A chain grate is a mechanized combustion device in which a chain drives grate bars to move like a conveyor belt, enabling automatic fuel feeding, continuous combustion, and automatic ash removal.

Operating Process:

Fuel falls from the hopper at the front of the boiler and enters the furnace chamber as the chain moves slowly. On the grate, the fuel sequentially undergoes five stages: preheating, drying, ignition, combustion, and complete combustion, before finally tumbling off the end of the grate into the ash discharge hopper.

II. Key Features of the Chain Grate

• Mechanization and Automation

It achieves continuous automation of coal feeding, combustion, and ash removal, reducing labor intensity and improving operational efficiency.

• Continuous Combustion and Uniform Feeding

Fuel falls from the coal hopper into the furnace and moves slowly with the grate, sequentially completing the processes of drying, volatilization, combustion, and complete burning, resulting in a stable firebed.

• Smooth Operation and Low Failure Rate

As the fuel moves in tandem with the grate, there is no violent relative motion between fuel layers. This “stationary combustion” mode reduces fly ash generation, minimizes mechanical wear, and ensures highly stable system operation.

• Wide fuel compatibility

Not only is it suitable for high-quality coal, but thanks to technological improvements, it also serves as an efficient combustion solution for biomass (such as wood chips and pellets).

III. Technical Advantages of TGBOILER

In our DZL Boiler and SZL series boilers, the chain grate has been specially optimized:

Segmented design: Reduces fuel leakage and makes grate bar replacement very simple.

Heat-resistant materials: Made of special cast iron with strong resistance to thermal deformation, offering a service life 2–3 times longer than that of ordinary grates.